Thylacoleo carnifex
"Marsupial Lion"
Extinct
By Molly Kalafut
Quick Facts
- Names: Thylacoleo carnifex, Marsupial Lion
- Scientific Classification: Marsupial, Order Diprotodontia, Family Thlacoleonidae, Genus Thylacoleo, Species carnifex
- Status: Extinct, probably within the last 6,000-50,000 years
- Fossils First Found: 1830s by Thomas Mitchell in New South Wales, Australia
- First Described By: Sir Richard Owen, 1859
- Lived During: 25 million years ago Oligocene period and common in Pleistocene
- Range: Throughout Australia, primarily eastern
- Biology: Known for short skulls, powerful jaws, huge incisor teeth, sharp cheek teeth called "carnassials", semi-opposable thumbs with retractable claws
- Weight/Size: About 100-130kg (200+ pounds), similar to African lion, reaches 2 meters long
- Teeth/Jaw: Strongest bite of any living or extinct carnivore. Specialized carnassial teeth for slicing meat, premolars that can reach 2.24" long
- Diet: Carnivorous. It's teeth-marks have been found on bones of the largest marsupial ever, the extinct 3-ton "Diprotodon australis" wombat
Introduction
The marsupial lion is an extinct large carnivorous marsupial from Australia that is compared to the saber-toothed cats of the Americas.
|
Marsupialia |
|
| Order | Diprotodontia |
| Family | Thlacoleonidae |
| Genus | Thylacoleo |
| Species | carnifex |
Names:
- Latin: Thylacoleo carnifex
- Common: Marsupial Lion
Though more closely related to wombats than real lions, Thylacoleo carnifex was called the "marsupial lion" because of its similar size to an African lion, predatory nature and cat-like skull. The name translates to "marsupial lion executioner", or "meat-maker". The name "carnifex" for this animal was first used in 1859 by Sir Richard Owen.
History
Timeline
The marsupial lion's family lived at least 25 million years ago in the rainforests of Queensland during the Oligocene period. Since that time 8+ different species of marsupial lions have been identified, culminating in Thylacoleo carnifex. They were the largest mammal predator in Australia during the Ice Age and were common during the Pleistocene period. Skull and teeth fragments have been found throughout Australia, but the Western and Tasmanian specimens are thought to be smaller than those in the east.
Sources conflict on when they became extinct, but most agree that it was within the last 50,000 years:
- News articles from 2005 suggest within 45,000 years
- "Britannica encyclopedia" suggests within 26,000 years
- "Thylacoleo Remembrance" suggests within 18,000 years
- "Last Tasmanian Tiger" suggests within 10,000 years
Fossil Collection
Thomas Mitchell collected the first marsupial lion remains from the Wellington Valley region in New South Wales in the early 1830s. More skull fragments were found in 1845, southwest of Melbourne, Victoria. The marsupial lion (Thylacoleo carnifex) was described in detail about 1859 by the noted British paleontologist Sir Richard Owen (known as the first person to use the term "dinosaur"). He described the marsupial lion as "one of the fellest and most destructive of predatory beasts".
Order Diprotodontia
The two front incisor teeth place the marsupial lion in the Order Diprotodontia, which includes the primarily herbivorous kangaroos, koalas, possums and wombats. Sir Richard Owen stated in 1866 that the marsupial lion "exemplifies the simplest and most effective dental machinery for predatory life and carnivorous diet known in the mammalian class, It is the extreme modification, to this end, of the Diprotodont type of Marsupialia".
Family Thlacoleonidae
It has been placed in its own family (Thlacoleonidae) but there is some disagreement that they may have descended from either the family of the pygmy possums (Burramyidae) or wombats. In the late 1800s and early 1900s it was thought they might be more accurately described as hyenas, but that was abandoned due to the lack of "cingulum" structure to protect the teeth from bone crunching.
Biology
The cat-like "marsupial lion" had short skulls, powerful jaws, huge incisor teeth, sharp cheek teeth and semi-opposable thumb claws.
Size
Marsupial lions are often described as close in size to African lions. An article by Dr. Stephen Wroe noted that while over time there have been many conflicting reports of the marsupial lion's weight - ranging from 20kg to 100 kg - recent research places their weight firmly at 200+ pounds (100-130kg). This is exceptionally large as only about 5 placental cats in the last 40 million years exceeded 100kg. The marsupial lions could reach a length of about 2 meters. They may have been shorter than today's large cats, but weighed more given their height. Males may have been larger than females.
Skull
A number of skull fossils have been found. Like many carnivorous mammals, their skulls are short and broad (brachycephalic). One example of the skull was 26cm long and 23cm wide. The jaws are also short, and their close proximity to the joints that help the jaws open and close help them apply more power and force to their bites. The placement of the eyes allow for binocular vision to assist hunting. Interestingly, both the Australian marsupial lion and the South American marsupial saber-tooth tiger have a "postorbital bar" (a connection of bone in the skull) that is rare in carnivores.
Teeth
|
Dentition |
Marsupial Lion (Top/Bottom) |
People (Top/Bottom) |
| Incisors | 3/1 | 2/2 |
| Canines | 1/0 | 1/1 |
| Pre-Molars | 3/3 | 2/2 |
| Molars | 1/2 | 3/3 |
| Total | 26 | 36 |
Marsupial lions are known for their teeth and powerful bite from fossil specimens. Interestingly, they didn't have canine teeth like wolves or lions and were reduced to mere pegs. Instead they had large first incisors, described by Sir Richard Owen in 1871 as "adapted for piercing, holding and lacerating, like the canine of a carnivore". They had blade-sharp cheek teeth 3rd premolars called specialized "carnassial" teeth that were more effective for slicing meat than the teeth of placental cats. The molar teeth were small, but their posterior premolars were very large and could reach 2.24" long. The marsupial lion has been described as possibly the most specialized mammalian carnivore ever.
Bite
Research in 2005 revealed that for their size, the marsupial lion's bite was more powerful for its size than any known animal, living or extinct. The study compared 39 carnivorous animals, including the saber-tooth tiger, lions, wolves, jaguars, leopards, spotted hyena and Tasmanian devil. After compensating for body mass, the marsupial lion was judged the most powerful biter of all animals overall, delivering bites 3 times more powerful than placental lions twice their size. Interestingly, another marsupial, the Tasmanian Devil, was judged the most powerful biter of a living species. It is theorized the short skull and smaller brain size of marsupials may allow room for more powerful development of the jaws.
Paws
The paws of the marsupial lion were more suited to climbing, gripping and holding rather than walking or running. Similar to placental cats, the marsupial lion's weight was supported on the ends of the toes. Both the front and back paws had a strong grip due to the thumbs being opposable to the the wrist bone. The front thumbs also had a hooded, retractable claw that was far longer than the small claws on the rest of the digits and useful for slashing. It is thought to be an arboreal hunter in forests, but fossils have been found in areas that were plains when the animal was alive. It was able to slash prey with it's claws and grasp it using the thumbs. The hindfoot shows syndactyly similarly to many other possums, with the 2nd and 3rd digits fused with a sheath of skin.
Diet
"Overall, the picture of Pleistocene Marsupial 'Lion' biology indicated by these findings is of a muscle-bound, 'purpose-built' ambusher, wrestler and dispatcher of large prey. This beast probably didn't waste time taking out small fry." -Dr. Stephen Wroe
Of about 60 mammals in Australia that have exceeded 10 kilograms in weight, only 3 were carnivorous. The marsupial lion is one of those 3. Since the marsupial lions did not have teeth modifications to assist bone cracking, it is thought they ate primarily flesh, internal organs and soft tissue. The marsupial lion could slash with their long claws, grasp prey with their semi-opposable thumb equipped with retractable claw, then stab or strangle it with the large incisors.
Since the 1850s there have been arguments about their primary diet, with suggestions ranging from carnivorous to scavenger to herbivorous. Research in 1982 indicated the tooth enamel was worn in patterns similar to carnivores, but not herbivores. They concluded the lower teeth would stab or pierce while the upper teeth held the food, then the large premolars would slice and shear it like a knife-cut.
The largest prey they could have brought down was the largest marsupial ever, the rhinoceros-sized "Diprotodon australis" wombat. Marsupial lion teeth marks have been found on their bones. Marsupial lion teeth-marks have been found on a variety of fossilized herbivores, especially on the rib bones. To quote Dr. Stephen Wroe, the marsupial lion may have used "its massive bolt cutter-like cheek teeth to scissor through the windpipe or vital blood vessels of big animals. This would have hastened the demise of the prey, adding rapid major blood loss to asphyxiation."
It has been described as an arboreal hunter and remains are often found in places that used to be forests. Due to its large size it probably couldn't prey on the quick-moving arboreal animals, but like jaguars it may have dragged its food into trees to eat - or it was too large to do that well. Suggested foods the marsupial lion may have eaten include mammals, birds, plants, fruit, kangaroos (including the extinct Sthenurus kangaroos), wombats, crocodile eggs and cycad pith.
Sources
"Aussie Lion Beats All In Bite Test", AAP, 04/02/2005
"Ecological Imperialism: The Biological Expansion of Europe, 900-1900 (Canto)", Alfred W. Crosby, Published 06/251993
"Extinct Animals - Thylacoleo carnifex", Government of South Australia, Department of Environment and Heritage, 07/22/2004
"Life : A Natural History of the First Four Billion Years of Life on Earth", Richard Fortey, Published 09/07/1999
"Marsupial", Encyclopędia Britannica Premium Service, Accessed 04/06/2005 found at http://www.britannica.com/eb/article?tocId=51357
"Marsupial Lion Had Fierce Bite", New Zealand Herald, 04/04/2005
"Move Over Sabre-Tooth Tiger", Stephen Wroe, Nature Australia Volume 26, no 10:44-51, 2003
"No Lion: Marsupials Have Fiercest Bite, Study Says", James Owen, National Geographic News, 04/05/2005
"No Turning Back: The Life and Death of Animal Species", Richard Ellis, Published 08/01/2004
"Tasmanian Tiger: The Tragic Tale of How the World Lost Its Most Mysterious Predator", David Owen, Published 03/14/2004
"The Future Eaters: An Ecological History of the Australian Lands and People", Tim F. Flannery, Published 11/01/2002
"The Last Tasmanian Tiger: The History and Extinction of the Thylacine", Robert Paddle, Published 09/04/2002
"The Tribe of Tiger: Cats And Their Culture", Elizabeth Marshall Thomas, Published 06/2001.
"Who Or What Was The Thylacoleo Carnifex", Accessed 04/04/2005